Penetrating Fluid

Rusty Nuts and Bolts?

Make Your Own Super Rust Penetrant!

Since its invention in 1953, WD-40 has been the go-to solution for many household and garage problems. Over the years, other companies have come up with their answer to WD-40’s penetrating properties such as Liquid Wrench and Kano Kroil. Others have tried their own home-brewed concoctions in the never-ending battle against rusted nuts and bolts. Our favorite is a 50/50 mix of acetone and Dexron/Mercon Automatic Transmission Fluid.

Simply mix one part acetone and one part ATF in a re-fillable spray bottle and go to town. The idea is to thin the ATF with the acetone so it will penetrate and seep into and between surfaces. The acetone will evaporate, leaving the oil to do its job. Because the acetone evaporates so quickly, it’s a good idea to mix this in small batches.

Skeptical? We were too. Then we did some poking around on Google and found that in the April 2007 issue of Machinist Workshop Magazine, they performed subjective independent testing of penetrating oils using a single steel bar with 1/2″ x 20 nuts torqued to 50 ft/lbs and treated with a 10% salt water solution that was allowed to rust.

Listed are the chemicals tested and the respective required removal torque: